Molten metal temperature indicator



Sem 26, 1950 T. F. ALLY 2523,4n

MOLTEN METAL TEMPERATURE INDICATOR Filed March 1 4, 1947 INI/EN TOR. THON/4S F A L Y A TTOPENEYS Patented Sept. 26, 1950 MOLTEN METAL TEMPERATURE INDICATOR Thomas F. Lally, Hamburg, N, Y., assignor to Republic Steel Corporation, Cleveland, Ohio, a corporation of New Jersey Application March 14, 1947, Serial No. 734,577

The present invention relates to the art of heat and temperature measurement and is particularly concerned with a novel, accurate and economical method of determining the temperature of molten metals and With novelmeans implementing that method. l

At certain stages in the production or refinement of metals it is necessary to determine accurately the temperature of the metals in molten form.. In the production of open hearth steel, for instance, the temperature at which the steel is poured from the furnace has an important bearing upon the character of the final steel product and on the economy of the entire operation. The optimum tapping temperature will vary with the composition of the melt in the furnace, but in any event wil-l always be approximated as closely as possible by the operator at the time tapping is begun. Because of the obvious serious difficulties of tapping at a temperature which is too low, however, most heats are tapped at temperatures substantially above their optimum and numerous detrimental results are thus incidentally incurred. For instance, time and tonnage are lost, the life of the furnace brick work is substantially reduced, furnace bottoms are excessively eroded, ladle life is shortened, oxidation losses of metal are high, phosphorusreversion is substantial, and melt heating costs are materially increased. All these difficulties are suffered for lack of a suitable method for accurately and rapidly determining the temperature of open hearth heats prior to tapping. Pyrometers may be used effectively in determining heat temperature after the tap hole of the furnace has been opened, when increasing the temperature of a heat in the furnace is not feasible. If the temperature of the heat is too low when the furnace, is tapped, a considerable loss of metal results, it being impossible to remove substantially all the metal from the furnace in that condition. Means which would remove the expensive guess work presently necessaryin connection with producing open hearth steels, as well as other metals, has therefore long been an insistent demand of manufacturers of such metals.

My present invention fully responds to this demand and provides for the first time, to my knowledge, a method and means whereby the control of tapping temperatures of open hearth heats may be closely controlled so that heats can always be tapped at substantially exactly their optimum tapping temperatures. Furthermore, this invention enables the rapid and accurate determination of molten metal temperatures in both ferrous and non-ferrous metal elds.

3 Claims. (Cl. 'i3-A32) The method of my invention is based upon my discovery that the length of a course ofl flow of molten metal bears a direct relationship to the initial temperature of the molten metal, and, in fact, is so closely correlated to that temperature that very, accurate measurements can readily be made of the temperature of the source of molten metal by what at first blush appears to be an impossibly crude process.

Briefly, this invention comprises the step of flowing molten metal, the temperature of which is to be determined, in contact with a suitable surface, permitting the metal to cool and solidify in contact with the said surface, and comparing the length of such ow with the lengths of flow in contact with said surface of a plurality of samples of metal having substantially the same heat and temperature and viscosity characteristics as said molten metal and having known initial temperatures.

A novel and particularly satisfactory type of implement with which to carry out the present method is that illustrated in the accompanying drawings which form a part of this specification, and in which,

Figure l is a top view of one-form of device of this invention;

Figure 2 is a view taken on line 2-2 of Fig. l; and,

Figure 3 is a View in elevation looking at the right hand end of Fig. 1.

In general, the illustrated device comprises a metal block B having a passageway A to receive molten metal and to indicate the temperature of said Vmolten metal by the extent of flow of said metal through the aperture prior to solidication.

Block B is a substantially rectangular, relatively longand thin block formedof two similarly shaped plates I0. Th'e plates are suitably secured together to define a block by means of clamps (not shown). The corners of the plates are provided with apertures to receive dowels I2.

The passageway A is dened by grooves in opposing surfaces of the plates IIJ` and is substantially V-shaped. The passageway extends entirely through the block B, opening at one end through the top surface thereof and at the other end through the upper portion of an end surface of the block. One of the legs I4 of passageway A, comprising a sprue, is disposed at substantially right angles to the top surface of the block and extends downwardly therefrom to a point near the bottom of the block, where it communicates with the other or riser leg I5 of the passageway, which extends upwardly and terminates in the upper portion of an end of the block. The sprue I4 is enlarged adjacent the top portion of the block, thus providing a funnel shaped opening to receive molten. metal samples to be temperature tested.

One of the plates bears a temperature scale C which is along the portion of the groove which defines with a similar groove in the other plate the riser leg I5 of the passageway.

The vertex of the V-shaped passageway A,

, which is adjacent the lower portion of the block B, includes an angle of about 60 with the bottom surface of the block. These angles are not critical andmay vary widely from block to block but in any event the sprue should extend generally downwardly into the block and the riser should extend generally upwardly from the point where the sprue opens into the riser.

The device may be calibrated by separately casting in the block a plurality of samples of molten metal having known initial temperatures varying over a substantial range, and accordingly marking a temperature scale on either or both plates I of the block along the grooves defining passageway A.

In using the illustrated device, I fasten the plates I0 together in substantially fluid tight contact to dene calibrated passageway A by means of suitable clamps, dowels I2 being disposed in registered apertures in the corners of the plates. I then rapidly charge into the dared open end of sprue I4 a. quantity of molten metal, the temperature of which is to be determined, until the sprue is substantially iilled with the metal. After the metal sample has solidified within the block B, I remove the dowel pins, open the block by removing the clamps and dowels I2, and read the temperature scale C opposite to the end of the metal casting which indicates the temperature of the molten metal when it was introduced into the block B.

Accurate reproducible results can ordinarily be obtained even though the sprue is not filled as described, but I have found that the most reliable practice is as described, especially in connection with the determination of initial temperatures of molten steels, cast irons and non-ferrous metals, such as copper and zinc. Apparently the head pressure upon the metal at the vertex of the aperture and in the riser leg I5 thereof is of some importance so far as the length of iiow in said leg is concerned, and it is desirable therefore to charge the sprue I4 as rapidly as possible with the molten sample to minimize the difference in head pressure eiect from sample to sample.

Having thus described the present invention so that those skilled in the art may practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed.

What is claimed is:

1. A device for determining the temperature of molten metal comprising a metal block composed of a pair of plates having opposed surfaces grooved to delne a passageway for molten metal constituting a generally downwardly extending sprue and a generally upwardly extending vented riser, said riser being calibrated to indicate the temperature of molten metal introduced into the sprue.

2. A device for determining the temperature of molten metal comprising a. metal block composed of a pair of plates having opposed surfaces grooved to define a passageway for molten metal constituting a generally downwardly extending sprue and a generally upwardly extending vented riser, said sprue being disposed at substantially right angles to said top and bottom surfaces and said riser being disposed at substantially a degree angle to the sprue and being calibrated to indicate the temperature of molten metal introduced into said sprue.

3. A device for determining the temperature of molten metal comprising a metal block composed of two plates having opposing surfaces grooved to define a passageway in said block and having registered apertures to receive dowel pins, and dowel pins disposed in said latter apertures,

said passageway being of substantially V-shape and comprising a generally downwardly extending sprue and a generally upwardly extending open riser, and said riser being calibrated to ndicate the temperature of molten metal introduced into said sprue.

THOMAS F. LALLY.

REFERENCES CITED The following references are of record 1n the Iile of this patent:

UNITED STATES PATENTS Name Date Currie Feb. 19, 1946 OTHER REFERENCES Number 

